Perhaps you should try some spelling variations:
"vu tich nganh cong khi đong luc" » "vu tich ngan cong khi đong luc", "vu tich nang cong khi đong luc", "vu dich ngan cong khi đong luc", "vu tich nhanh chong khi đong luc", "vu tich thanh cong khi đong luc", "vu tich nganh cong thai đong luc", "vu tich nganh khong khi đong luc", "vu tich nganh cong ha đong luc", "su tich nganh cong khi đong luc", "va tich nganh cong khi đong luc", "suc tich nganh cong khi đong luc"
"su sach ngan co khi đong luc" » "su sach ngon co khi đong luc", "su sach nha co khi đong luc", "su sach han co khi đong luc", "so sach ngan co khi đong luc", "vu sach ngan co khi đong luc", "su sach nganh co khi đong luc", "su sach nhan co khi đong luc"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("vu tich nganh cong khi đong luc") or ("su sach ngan co khi đong luc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("vu tich nganh cong khi đong luc") OR ("su sach ngan co khi đong luc")).
• Removing quotes may allow a broader search: (( vu tich nganh cong khi đong luc ) or ( su sach ngan co khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (("vu tich nganh cong khi đong luc") or ("su sach ngan co khi đong luc"))*.